1. Field of the Invention
The present invention relates to a radio relay apparatus for relaying communications between a base station and a mobile station in a mobile communication system, a monitoring apparatus for monitoring a mobile communication system, and a method of determining an identification code of the radio relay apparatus.
2. Description of the Related Art
In a mobile communication system, a base station communicates with mobile stations located in a cell covered by the base station. However, even within a single cell, there may be places not suitable for direct radio communication because of shielding due to buildings or other reasons, so that signals from the base station can hardly reach the mobile stations at these places. For this reason, radio relay apparatuses are installed to relay the radio communications between the base station and the mobile stations.
In addition, a monitoring apparatus for monitoring the radio relay apparatuses may be installed in a mobile communication system. Each of the radio relay apparatuses transmits information required for monitoring to the monitoring apparatus. In order for the monitoring apparatus to identify the source of transmission of the monitoring information, each of the radio relay apparatuses transmits the monitoring information with an identification code included therein.
The identification code of a radio relay apparatus is determined in the following way. When a radio relay apparatus is newly installed, a maintainer specifies a base station according to its location as the target to be relayed to/from by the radio relay apparatus. Then, in conjunction with an identification code of the specified base station, the maintainer determines an identification code of the radio relay apparatus and writes the determined identification code to the radio relay apparatus. By the making of the identification code of the radio relay apparatus in conjunction with the identification code of the base station, the base station is enabled to determine all the call areas covered by itself by using the identification codes of the radio relay apparatuses.
When problems occur in a base station, or a base station is newly installed, the target of relay of a radio relay apparatus changes. In this case, the maintainer specifies another base station as the new target of relay, and in a similar way, the maintainer determines an identification code of each radio relay apparatus in conjunction with the identification code of the newly specified base station, and then writes the determined identification code to the radio relay apparatus.
As described above, in the related art, each time a radio relay apparatus or a base station is newly installed, the target of relay of a radio relay apparatus changes, the maintainer has to go through the above procedure, that is, searching for a base station that is to be the new target of relay, determining an identification code of each radio relay apparatus in conjunction with the identification code of the newly specified base station, and writing the determined identification code to the radio relay apparatus. This operation is cumbersome, and may result in mistakes because it is performed manually. As a result, it usually time consuming to start operations of a radio relay apparatus, and radio communication areas cannot be formed quickly.